Pros: Flat organization. Good free food, summer parties, several smart people with big egos. Relaxed dress code.

Cons: Flat organization with training focused primarily on traders. One has to become bosses pet to get good work and raises. Highly skewed against women. Too many egos of long timers.

Pros: Free breakfast and lunch (and dinner, if you decide to bring home a little something). Gym inside building, dry cleaning services. If you're a technologist, you're given a lot of freedom with regards to project development. Managers generally recognize when an employee has done good work. Casual dress code everyday, even more relaxed on fridays in the summer. While advancement within the company is generally not available, career advancement overall is definitely possible since great responsibilities are placed upon individual developers. Performance-based bonuses for technologists (although the market can also influence the overall bonus).

Cons: One downside is that the market itself can affect any performance bonuses. A trade gone bad in one division can lead to employees in another division getting their bonuses cut.

Pros: Management is open to developers testing new technologies. Interesting speakers in all facets of tech and business come in for sponsored talks. The owner is easy to talk to. Coworkers genuinely want to improve their tech skills and help each other.

Cons: Adoption of new tools/systems can be too fast; causing a lack of consistent implementation across teams.